Bonded fibrous products and method of manufacture



April 1957 R. H. SONNEBORN- ETAL 2,790,741

BONDED FI BROUS PRODUCTS AND METHOD OF MANUFACTURE Filed Sept. 30, 1952 SONNEBQRN 7 BY THOMAS E- P IL [PPS mmvrozzs RALPH H ATTYs product itself.

United States Patent "ice BONDED FIBROUS PRODUCTS AND METHOD OF MANUFACTURE Ralph H. Sonneborn, Newark, and Thomas E. Philipps, Granville, Ohio, assignors to Owens-Corning Fiberglass Corporation, Toledo, Ohio, a corporation of Delaware Application September 30, 1952, Serial No. 312,198

8 Claims. (Cl. 154-101) In the past, various resinous products including resins in the form of granular powders and liquid resins have been applied to fibrous glass products as binding material to give the finished products integrity and strength.

Formerly, such liquid resins or granular powder resins have been applied in various ways including the use of spraying and dusting methods; however, the problem of obtaining the proper distribution of binding material throughout the product has always been present and not too successfully met by the former methods.

One of the methods used formerly in applying binder was to spray a water dispersion of the resinous material upon the fibrous glass as the fibers themselves were being formed. This method results in a product having fairly uniform binder distribution and good strength of product. However, this method makes it necessary, to drive ofi in subsequent heating operations a great deal of water or solvent dependent upon which medium is present. The heating step requires much time and the use of a great deal of energy.

Another method formerly used has been to form a mat of fibers upon which is dusted a powdered resinous material which can be set by application of heat to the mat. The products so formed tend to have a weak or low tensile strength and high ignition losses which indicates that the proportion of binder ingredient is too high without actually giving adequate strength in the The low strength results at least partially because of the non-uniform distribution of the binder throughout the mat.

It is an object of this invention to obtain uniform 'distribution of binder materials in fibrous mats and'the like.

It is also an object to provide a method of producing uniformly bonded mats of any thickness, including very thick mats;

It is a further object to provide a continuous method of producing mats having good integrity and high tensile strength.

It is an object to provide a method of reducingthe binder-to-fiber ratio while improving the quality of the final product.

Otherobjects will be evident from the description and drawings in which:

Figures laand 1b constitute a schematic view of ap-'" layers of the mat.

This apparatus is used to apply first a powdered res- -inous binderand then a sprayable liquid binder in such a manner that, although reduced proportions of binder are used, a better product is obtained because the uniformity of distribution of the binder is improved and 2,790,741 Patented Apr. 30, 1957 resulting higher strengths of the product are attained. The combination of the application of powdered and liquid binders to a fibrous mat and especially the application of the powdered and liquid binders in the sequence used in this invention is believed to be new in the art and entirely unobvious for it is a radical departure from the sequence generally used in applying liquid and powdered materials on the same product. Normally, it would seem best to apply first the liquid and then the powder; however, it has been discovered that the best results are attained by applying the binder materials in the reverse of the obvious order as will be described in the following paragraphs. Furthermore it has been discovered that the total binder content can be lowered even though two forms of binder are applied to the product.

.In Figure 1A, the apparatus comprises a cutter 12, into which a plurality of strands 11 of fibrous glass are being fed. The cutter 12 comprises a pair of opposed rolls 13 and 14, the former being a rubber-covered roll 'andthe latter being provided with cutterbars 15, 15 arranged longitudinally across the periphery of the roll. Roll 13 is driven by a suitable mechanism indicated by numeral 16. Roll 14 is in turn driven through the gear train including gears 17 and 18.

A conveyor belt 19, mounted on rolls 21 and 22, lies generally below the cutter 12. Conveyor belt 19 is a mesh belt and is provided with a suction box 23 having 'a vacuum line 24. Chopped strands 25, 25 are retained .by members 26, 26. An inclined conveyor belt 27,

chopped fibrous material 38. This mixture 38 is shown being deposited on conveyor belt 39 which is mounted Lupon rolls 41 and 42. Conveyor belt 39 is provided with a suction box 30 having vacuum line 40.

. Conveyor belt 39 and roll 42 appear in Figure 18 where a mat of chopped fibrous material and powdered binder 43 is shown passing over conveyor belt 39 after being formed thereon. Disposed above conveyor belt 39 1s a bank of spray nozzles 44, 44 mounted upon manifold 45 to which is supplied a suitable liquid resinous binder. Next to conveyor belt 39 is another conveyor belt 46 which is mounted upon rolls 47, 48. Between rolls 42 and 47 is mounted a bank of nozzles 49, 49

I mounted .upon manifold 51 which manifold is supplied w th a liquid resinous binder shown being sprayed upon the mat 43.

Belts 19 and 39 are mesh belts through which air can pass while belt 46 is preferably one which can withstand high temperatures but need not necessarily be one through which air can pass. About conveyor belt 46 is oven 52 heated by any suitable heat source and designed to .fuse and heat set the binders which have been applied f to the mat product.

by means not shown.

The final product 53 is rolled up In using this apparatus, the strands 11 are pulled from a creel, not shown, containing packages of the strand and are threaded between idler roll 10 and rubber covered roll 13. The cutter 12 is then started so that the strands 11, 11 are pulled between rolls 13 and 14 and are chopped into lengths of from /2 to 5 inches as may be desired. The chopped strands then fall, due to gravity,

. upon conveyor belt 19 and are pulled downwardly upon the belt by the action of suction box 23. The retainfstrandsof fibrous material.

larged is shown.

ing members 26, 26 confine the chopped strands as they are falling from the cutter 12, and after the chopped strands are pulled downwardly into a mat upon conveyor belt 19, they move toward conveyor belt '27 aiid'p'ro'cecd upwardly upon this belt as can be seen 'in Figure lA. A powdered resinous material comprising a plien'ol formaldehyde resin is then applied through the bottom of hopper 32 and the powdered binder passesdownwarm throughout the extent of the mat of fibrous 'matei'ial. The :mat then passes into a picker roll34 which very intimately mixes powdered binder arid short chopped The picker roll also destroys the integrity of the matSLresultirigin' the'deposition of a mixture of fibrous rnateri aland "powderedbinder upon conveyor belt'39 in that area b etween retaining members 36 and 37. The mat of clioppedi fiber and powderedbi nder 43 is then 'forrn'edby 'the action of suction box30' and this 'rnat passes over conveyor belt 39 and is sprayed both on top' andbottonfby' nozzles 45, 45 and 49, 49. 'A' liquid resinous'b'indercompris ing a waterdis'persion of phenol formaldehyde resin is used to coat the upper'and'l'o'wer surracesbr the met. The mat proceeds over conveyor belt '46 th'roii'gh the heated oven '52 'wherein the powderedbinder'isfused and the liquid binder which covers the upper and lower surfaces of the mat' is heatset andbecomesan'integral part of the finalproduct.

In Figure 2 a view of the final :produ'ct' greatly 'en- The inner fibers75'4 of this product are bonded one to another chiefly by s pherical' particles of binder formed by fusing the powdered binder which has been applied. The upper and lowersurfaces 55 of the product are bonded one 'to another 'mainly by a thin coating of resin formed from a liquid film applied'by sprayrlozzles 45, 45'2ind 49, '49.

Various binders may be used; both'pow'dered and liquid binders maybe chosen for theirparticular desirable properties. For instance, phenol formaldehyde, urea formaldehyde, polyvinyl acetate, melamine and polystyrene resins, polyester resins such as those formed from the reaction of diethylene glycol'and maleic anhydride cross-linked with dia'llyl phthalate,' resins 'formedfrom a polyol and fumaric acid, 'and others may beiised. Anyresin which may be heat treated to form abirider for the fibrous'material may be 'used.' It is intended, however,touse a combination of a dry particulate binder material along with a liquid'binder materiahwhichliquid may be either in'the form of asolution in a solvent system oran emulsion or dispersion'in either a compatible liquid or a water system.

Oven temperatures may vary according to the particular resins used. However, the temperatures will generally vary from about 180 F. to about 700 "F; and possibly as high as- 1000 The percent-of solids inthe liquid binder -may-be varied as maybe necessary in forming handleableemulsions or dispersions of the different resins which are used. The emulsions .or dispersions mayvary from A: to 40% total solids dependent upon the resin used. Low

percentage emulsions of polyester type resin-s may be used,

percentage of the final resin, content mayresult from addition of powdered binder. In fact, '90or' inbre percentof the final resin content may be due to eithef'the powdered or the liquid resin. Preferably the total binder percentage will comprise 40 to"60% binder added as a powder and 60 to 40% binder-addeda's anemulsion or dispersion.

of the mat.

It has been discovered that great savings can be realized by adding the resinous binder in two forms, namely, a powder form and a liquid form. Furthermore, it has been discovered that by adding the powdered binder first, it is possible to get complete uniformity of binder distribution within the mat since it is believed the powdered binder drops downwardly throughout the mat when it is applied and then subsequently the liquid binder coats the surfaces and the interstices of the mat to produce a mat having great integrityand tensile strength. To add the liquid and powdered binders in another sequence would result in all or a greater proportion of the binder being deposited upon the surface of the mat and would result in a weak and non-uniform product.

Although in the example illustrated by the drawings, the powdered binder and fibers of the mat 31 are intimately mixed by disrupting the mat integrity, it should be understood that violent action neednot be taken. The mat as first formed can remain intact throughout the treatment and the powdered binder can -be distributed throughout the mat by shaking the mat.

The methods and apparatus of this invention can be usedto produce mats of any fibrous material including hair, straw glass, felt, cellulose, silk, wool, and any of the synthetic fibers, including those comprising a polyamide, a polymer of vinyl chloride and acrylonitrile, polyacrylonitrile, a polymer of ethylene glycol and dimethyl terephthalate, a polymer of vinylidine chloride and vinyl chloride, and others.

Although a particular embodiment of the invention has been disclosed, obvious modifications may be made within the spirit and scopeof the following claims.

We claim:

'1. A method of producing a resin bonded fibrous glass lmat comprising chopping and collectingfibrous glass materi al in the form of an advancing mat, distributing on said advancing mat a powdered heat setting resinous binder, mechanically disrupting the fibrous glass material within said advancing mat to form an intimate mixture of said fibrous glass material and said powdered resinous binder, collecting said mixture in the form of an advancing mat, spraying a heat setting, resinous binder in liquid 'form upon the advancing mat, and subjecting said mat to an elevated temperature to heat set the resinous binders thereon.

2. An integral mat of haphazardly arranged fibers of glass bonded together by a resinous binder, the inner fibers of said mat being bonded one to another chiefiy by fused particles of a dry resinous binder, and the outer fibers of which are bonded one to another by a uniform coating of resinous binder material, the binders being selected from the group of resins consisting of phenol formaldehyde, urea formaldehyde, polyvinyl acetate, melamine,- polystyrene, and polyesters.

3. The mat-of claim 2 wherein said fused particles of dry resinous binder comprise from 40 to 60 parts by weight --ofthe total weight of the resinous binder, and said uniform coating of resinous-binder comprises from 40 to 60 parts by Weight of the total weight of resinous binder, said resinous binder being from 4 to 15 percent by weight 4. A mat of haphazardly arranged chopped textile 'strands of glassbonded with a phenol formaldehyde hinder, the chopped textile strands of the body of said mat being'bonded one to another chiefly by fused particles A of dry phenol formaldehyde binder, the chopped textile "strands at the surfaces of said mat being bonded one to =another by athin coating of phenol fonmaldehyde resin binder, said fused particles of a dry phenol formaldehyde binder comprising from 40 to 60 percent of the total weight of binder and said thin coating of resinous binder comprising from 40 to 60 percent of the total weightof binder,

' 'the total binder content being from 4 to 15 percent by weight.

strands of glass bonded with a heat setting resin, the chopped textile strands of the body of said mat being bonded one to another by particles of a polyester resin applied as a powder, the chopped textile strands at the surface of said mat being bonded one to another by a coating of polyester resin applied as a liquid, said par ticles of resin applied as a powder comprising from 40 to 60 parts by weight of the total weight of the resin and said coating of resin applied as a liquid comprising from 40 to 60 parts by weight of the total weight of resin, the total resin content being from 4 to 15 percent by weight of the mat.

6. The mat of claim 5 wherein the polyester resin is one produced by the reaction of diethylene glycol and maleic anhydride cross-linked with diallyl phthalate.

7. A method of producing a resin bonded fibrous glass mat comprising chopping and collecting fibrous glass strands to form an advancing mat, introducing into said advancing mat a powdered resin selected from the group consisting of phenol formaldehyde, urea formaldehyde, polyvinyl acetate, melamine, polystyrene and polyester resins, intimately mixing said fibrous glass strands and said powdered resin in said advancing that, applying to at least one surface of said ladvancing mat a liquid resin selected from the group consisting of phenol formaldehyde, urea formaldehyde, polyvinyl acetate, melamine, polystyrene and polyester resins, and heating said mat to set the powdered and liquid resins, the powdered and liquid resins each being introduced in sufficient quantity to provide from 40 to 60 percent of the total binder content, said binder being from 4 to 15 percent by weight of the mat.

8. in a continuous method of producing resin bonded fibrous glass mat comprising cutting and collecting fibrous glass strands in the form of an advancing mat, the steps comprising applying a dry powdered polyester resin to said advancing mat, mechanically disrupting the integrity of said advancing mat and forming an intimate mixture of said fibrous glass strands 'of said advancing mat with said dry powdered polyester resin, collecting said intimate mixture in the form of a secondary advancing mat, applying a liquid polyester resin in the form of an emulsion to the surfiace of said secondary advancing mat, and heating to set both the dry powdered polyester resin and the liquid polyester resin, the powdered and liquid resins each being introduced in sufiicient quantity to provide from 40 to percent of the total resin eontent, the total resin content being from 4 to 15 percent by weight of the mat.

References Cited in the file of this patent UNITED STATES PATENTS 1,880,930 Elbel et al. Oct. 4, 1932 1,928,264 Powell Sept. 26, 1933 1,952,208 Hussey Mar. 27, 1934 2,057,166 Schur Oct. 13, 1936 2,288,072 Collins June 30, 1942 2,292,118 Guhl Aug. 4, 1942 2,372,433 Koon May 27, 1945 2,373,033 Kopplin Apr. 3, 1945 2,566,960 Philipps Sept. 4, 1951 2,569,169 Heritage Sept. 25, 1951 2,579,770 Uschmann Dec. 25, 1951 2,619,151 Sheidley Nov. 25, 1952 2,698,271 Clark Dec. 28, 1954 FOREIGN PATENTS 668,217 Great Britain Mar. 12,,1952 

1. A METHOD OF PRODUCING A RESIN BONDED FIBROUS GLASS MAT COMPRISING CHOPPING AND COLLECTING FIBROUS GLASS MATERIAL IN THE FORM OF AN ADVANCING MAT, DISTRIBUTING ON SAID ADVANCING MAT A POWDERED HEAT SETTING RESINOUS BINDER, MECHANICALLY DISRUPTING THE GLASS MATERIAL WITHIN SAID ADVANCING MAT TO FORM AN INTIMATE MIXTURE OF SAID FIBROUS GLASS MATERIAL AND SAID POWDERED RESINOUS 